Landing gear assembly for a trailer

ABSTRACT

A landing gear assembly for supporting a trailer. The landing gear assembly having first and second legs and a connecting member. Each leg is configured to selectively extend and retract in length. The connecting member operatively connects the first and second legs and is rotatable about an axis relative to the trailer and is axially movable between a first position and a second position. The first and second legs are each configured to extend in length a first amount per revolution of the connecting member about the axis of the connecting member when the connecting member is in the first position. The first and second legs are each configured to extend in length a second amount per revolution of the connecting member about the axis of the connecting member when the connecting member is in the second position. The first amount is greater than the second amount.

FIELD OF THE INVENTION

The present invention generally is directed to an apparatus forsupporting the front end of a trailer that has been detached from atruck, and more particularly to a landing gear assembly.

BACKGROUND OF THE INVENTION

One of the primary modes of shipping goods is by a truck pulled trailer.These trailers are equipped with a landing gear assembly that isretracted in a stored position above the ground while the trailer iscoupled to the truck. The landing gear assembly allows the trailer to beuncoupled from the truck when necessary. After placing the trailer in adesired location, the operator lowers the landing gear assembly intocontact with the ground. Once in contact with the ground, the truck isdisengaged from the trailer. Loading the trailer or placing the landinggear assembly in contact with relatively soft ground may affect thetrailer height above the ground. When the operator is ready to re-couplethe trailer to a truck it may be necessary to extend the landing gearassembly to raise the trailer.

Two speed landing gear assemblies have been developed to allow theoperator to more efficiently couple and uncouple trailers from trucks. Ahigh gear mode allows the landing gear assembly to move rapidly betweenthe stored position and the ground. Once in contact with the ground, thelow gear mode allows the landing gear assembly to lift the trailer. Theoperator turns a crank to raise or lower the landing gear assembly. Theratio of crank turns per inch of travel of the landing gear assembly issmaller for the high gear than for the low gear. In other words, thelegs will extend more per turn of the crank in high gear than in lowgear. Some two speed landing gear assemblies include a gear box attachedto one of the legs of the landing gear assembly. An input shaft turns anoutput shaft via the gears contained in the gear box. The output shaftinteracts with the lifting mechanism in both legs of the landing gearassembly to extend or retract the legs. In this configuration, the leghaving the gear box functions as a master leg and the other legfunctions as a slave leg.

Current landing gear assemblies split the mechanical advantage (createdby the gear box) between the two legs. As a result, relatively largeforces are placed on the lifting mechanism in each leg and the cross barbetween the two legs which affects the service life of the landing gearassembly. Another drawback of current landing gear assemblies is thatthe operator can only extend and retract the legs in high and low gearsfrom the master leg location. Still another limitation of currentlanding gear assemblies is that a single set of legs cannot be mountedin the multiple configurations required by the different types oftrailers.

SUMMARY OF THE INVENTION

The present invention solves these problems, providing a new landinggear assembly that eliminates the master and slave arrangement of theprevious landing gear assemblies and allows operation of the assemblyfrom either side of the trailer. In addition, the modular nature of thenew landing gear assembly allows a single configuration to be used inboth legs by changing the location of the mounting plate. In addition, aset of legs may be mounted in any configuration required by thedifferent types of trailers.

One aspect of the present invention is a landing gear assembly forsupporting a trailer. The landing gear assembly comprises a first leg, asecond leg, and a cross shaft. Each leg has a housing, an input shaft, agear mechanism, and an extension portion. The housing is adapted toconnect the leg to a trailer. The input shaft has a first end portionand a second end portion. The input shaft extends through the housingand is axially movable between a first position and a second positionand is rotationally movable. The gear mechanism is housed in the housingand has a high gear and a low gear. The gear mechanism is operativelyconnected to the input shaft such that the input shaft engages the lowgear when in the first position and the input shaft engages the highgear when in the second position. The extension portion istelescopically movable with respect to the housing and is operativelyconnected to the gear mechanism such that rotation of the input shaftmoves the extension portion with respect to the housing. The extensionportion is movable a first distance when the input shaft is rotated onerevolution while in the first position and a second distance when theinput shaft is rotated one revolution while in the second position. Thesecond distance is greater than the first distance. The cross shaft isadapted to operatively connect a first end portion of one of the inputshafts with a second end portion of the other of the input shafts suchthat axial movement of one of the input shafts of the first and secondlegs causes axial movement of the other of the input shafts of the firstand second legs and rotation of one of the input shafts of the first andsecond legs causes rotation of the other of the input shafts of thefirst and second legs. The first and second legs are adapted to beattached to a trailer and connected to one another with the cross shaftsuch that when the input shaft of one of the first and second legs ismoved to the first position the input shaft of the other of the firstand second legs is moved to the first position and when the input shaftof one of the first and second legs is moved to the second position theinput shaft of the other of the first and second legs is moved to thesecond position and when the input shaft of one of the first and secondlegs is rotated one revolution the input shaft of the other of the firstand second legs is rotated one revolution.

Another aspect of the present invention is a trailer having a landinggear assembly. The landing gear assembly comprises first and second legsand a connecting member. The first and second legs are attached to thetrailer and each leg is configured to selectively extend and retract inlength. The connecting member operatively connects the first and secondlegs and is rotatable about an axis relative to the trailer and isaxially movable between a first position and a second position. Thefirst and second legs are each configured to extend in length a firstamount per revolution of the connecting member about the axis of theconnecting member when the connecting member is in the first position.The first and second legs are each configured to extend in length asecond amount per revolution of the connecting member about the axis ofthe connecting member when the connecting member is in the secondposition. The first amount is greater than the second amount.

Another aspect of the present invention is a landing gear assemblycomprising a first leg that is adapted to attach to a trailer. The firstleg includes a first housing, a first input shaft, a first gearmechanism, and a first extension portion. The first input shaft has afirst end portion opposite a second end portion and extends through thefirst housing and is rotatable about a first axis relative to the firsthousing and is axially movable between a first position and a secondposition. The first gear mechanism has a first high gear and a first lowgear and is operatively connected to the first input shaft such that thefirst input shaft engages the first low gear when in the second positionand the first input shaft engages the first high gear when in the firstposition. The first extension portion is telescopically movable withrespect to the first housing and is operatively connected to the firstgear mechanism such that rotation of the first input shaft moves thefirst extension portion with respect to the first housing. The firstextension portion is movable a first amount when the first input shaftis rotated one revolution while in the first position and is movable asecond amount when the first input shaft is rotated one revolution whilein the second position. The first amount is greater than the secondamount. The first leg is adapted and configured to operatively connectto a second leg similar to the first leg and to be attached to a trailerin a manner such that axial movement of the input shaft selectivelyengages the high and low gears of the first and second legs.

Another aspect of the present invention is a method of extending alanding gear assembly. The method includes providing a trailer havingthe landing gear assembly. The landing gear assembly has first andsecond legs attached to the trailer and a connecting member operativelyconnecting the first and second legs. Each leg is configured toselectively extend and retract in length. The connecting member isrotatable about an axis relative to the trailer. The method furthercomprises causing the connecting member to rotate about the axis of theconnecting member at a first rate such that the first and second legsextend in length a first amount per revolution of the connecting member.The method further comprises causing the connecting member to rotateabout the axis of the connecting member at the first rate such that thefirst and second legs extend in length a second amount per revolution ofthe connecting member. The first amount is greater than the secondamount.

Other features and advantages will be in part apparent and in partpointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front plan view of a landing gear assembly of the presentinvention;

FIG. 2 is a side plan view of a leg of the landing gear assembly of FIG.1;

FIG. 3. is a sectional view taken along line 3-3 of FIG. 2;

FIG. 4 a is a top portion of the sectional view of FIG. 3 with thedevice in a first condition;

FIG. 4 b is a top portion of the sectional view of FIG. 3 with thedevice in a second condition;

FIG. 5 is an exploded view of the gear mechanism of FIG. 2;

FIG. 6 is another embodiment of the shift key;

FIG. 7 is a perspective view, without the housing for purposes ofclarity, of an upper portion of a leg of a landing gear assembly of thepresent invention;

FIG. 8 is a side plan view of the leg of FIG. 7;

FIG. 9 is a sectional view taken along line 9-9 in FIG. 8;

FIG. 10 is a perspective view, without the housing for purposes ofclarity, of an upper portion of a leg of a landing gear assembly of thepresent invention;

FIG. 11 is a side plan view of the leg of FIG. 10;

FIG. 12 is a sectional view taken along line 12-12 in FIG. 11;

FIG. 13 a is a landing gear assembly of the present invention shown in afirst mounting configuration; and

FIG. 13 b is the landing gear assembly of FIG. 13 shown in a secondmounting configuration.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, and more particularly to FIG. 1 a frontplan view of a landing gear assembly is shown generally at 30. Thelanding gear assembly comprises a first leg 32, a second leg 34, and aconnecting member 36. In the embodiment shown, the connecting member isa connecting shaft that is cylindrical. The first and second legs areconfigured to selectively extend and retract in length. A crank 38 mayby attached to the landing gear assembly and operated to extend andretract the legs. The first leg 32 includes a first mounting plate 40and the second leg 34 includes a second mounting plate 42. As will bediscussed in more detail below, the relative location of a mountingplate on a leg is the only structural difference between the first andsecond legs of a landing gear assembly. The mounting plates allow thelegs to attach to a trailer in a known manner.

Referring now to FIGS. 2 and 3, FIG. 2 shows a side plan view of thefirst leg 32 of the landing gear assembly 30 of FIG. 1. FIG. 3 shows asectional view of the first leg 32 taken along line 3-3 in FIG. 2. Thefirst leg 32 comprises a housing 46, an extension portion 48, a shoe 50,and an input shaft 52. The housing 46 is sized and configured to receivethe extension portion 48 such that the extension portion istelescopically movable with respect to the housing 46. The movement ofthe extension portion with respect to the housing is controlled by alifting mechanism.

The lifting mechanism comprises an externally threaded screw 54, a risernut 56, a stop plate 58 and a limit post 60. The stop plate 58 is fixedwithin the housing 46 and defines an opening that is sized to receivethe screw 54 in a manner such that the screw is free to rotate withinthe housing. A bevel gear 62 is sized and configured to engage a portionof the screw 54. The bevel gear 62 is further sized and configured toengage a set pin 64 extending from the screw. The set pin 64 and a flatwasher 66 on a first side of the stop plate 58 and a thrust bearing 68and locking member 70 on a second side of the stop plate 58 preventaxial movement of the screw 54 within the housing 46 while allowing thescrew 54 to freely rotate. The riser nut 56 is fixed to the extensionportion 48 and the riser nut defines an internally threaded central borethat is sized and configured to engage the external threads of the screw54. Rotation of the screw 54 causes the riser nut 56 to move axiallyalong the screw. Movement of the riser nut 56 along the screw 54 islimited by the locking member 70 and the thrust bearing 68 on one endand the limit post 60 on the other end. As the screw 54 is rotated andthe riser nut 56 is moved along the screw in the direction of the limitpost 60 the extension portion 48 is extended from the housing 46. In thealternative, as the screw 54 is rotated and the riser nut 56 is movedalong the screw in the direction of the locking member 70 the extensionportion 48 is retracted into the housing 46. When the riser nut 56 abutsthe locking member 70, the leg is in a fully retracted condition andwhen the riser nut abuts the limit post 60, the leg is in a fullyextended condition.

A gear mechanism is shown generally at 72 in FIGS. 3, 4 a and 4 b. Thegear mechanism engages the bevel gear 62. A shift key 74 provides aninterface between the input shaft 52 and the gear mechanism 72. Thehousing 46 defines a first opening opposite a second opening. The firstopening is sized to receive a first bushing 76 and the second opening issized to receive a second bushing 78. The first and second bushings aresized to receive the input shaft 52 and configured to allow rotation ofthe input shaft about an input shaft axis 80 with respect to the housing46. The first and second bushings are further configured to allow axialmovement of the input shaft in a direction of the input shaft axis 80.

The gear mechanism 72 comprises a low input gear 82, an idler gear 84and a high input gear 86. The low input gear 82 and the high input gear86 are sized and configured to receive the input shaft 52. A first inputwasher 88 is located adjacent the high input gear 86. A shift retainer90 positions a second input washer 92 adjacent the low input gear 82.The shift retainer 90 is partially cylindrical in shape (having ac-shaped cross section) and is configured to snap over the input shaft52. The first and second input washers 88, 92 and the shift retainer 90fix the position of the low input gear 82 and the high input gear 86between the first and second bushings 76, 78. An idler shaft 94 islocated parallel to the input shaft 52 and fixed in the housing 46. Anidler shaft tube 96 is sized to fit on the idler shaft 94 and to receiveand position the idler gear 84. The idler shaft tube 96 is configuredsuch that the idler gear 84 may rotate about the idler shaft 94 andengage both the low input gear 82 and the high input gear 86.

Referring now to FIGS. 4 a and 4 b, operation of the gear mechanism 72can be seen in a high gear condition and a low gear conditionrespectively. In FIG. 4 a, the input shaft 52 is in a first axialposition. In the first axial position, the shift key 74 is adjacent thefirst input washer 88 and in engagement with the high input gear 86.Rotation of the input shaft 52 causes the high input gear 86 to directlyengage the bevel gear 62 and to transfer the rotation of the input shaft52 to the screw 54 at a first ratio. In FIG. 4 b the input shaft 52 isin a second axial position. In the second axial position, the shift key74 is adjacent the second input washer 92 and in engagement with the lowinput gear 82. Rotation of the input shaft 52 causes the low input gear82 to engage the idler gear 84 which in turn engages the high input gear86. Rotation of the input shaft 52 is transferred by the shift key 74 tothe low input gear 82 to the idler gear 84 to the high input gear 86 tothe bevel gear 62 and finally to the screw 54 at a second ratio. Axialmovement of the input shaft 52 is limited by the first and second inputwashers 88, 92.

Referring now to FIG. 5, an exploded view of the gear mechanism 72 andthe shift key 74 can be seen. The input shaft 52 is shown in shadow forclarity. The low input gear 82 and the high input gear 86 have aplurality of shift key channels 98 that are shaped and configured toreceive the shift key 74. The high input gear 86 and low input gear 82are free to rotate about the input shaft 52 when not engaged by theshift key 74. For example, in FIG. 4 a, the shift key 74 directlyengages the high input gear 86 which transfers rotation of the inputshaft 52 to the screw 54. At the same time, the high input gear is alsocausing the idler gear 84 and the low input gear 82 to freely rotate.When the input shaft 52 is in a position between the first and secondpositions, the shift key 74 may engage both the low input gear 82 andthe high input gear 86 and in this position, the input shaft 52 will notrotate. The input shaft 52 will rotate when the shift key is inengagement with only one of the high and low input gears.

Referring now to FIG. 6, an alternative embodiment of the shift key isshown generally at 174. In this alternative embodiment, the shift key174 includes a low gear cog portion 182 and a high input gear engagingportion 186. The low gear cog portion 182 will replace the low inputgear 82. In the first axial position, the high input gear engagingportion 186 will be engaged with the high input gear 86 and the low gearcog portion 182 will not be engaged with the idler gear 84. In thesecond axial position, the high input gear engaging portion 186 will notbe engaged with the high input gear 86 and the low gear cog portion 182will be engaged with the idler gear 84.

Referring now to FIGS. 7-9, FIG. 7 is a perspective view of a anotherembodiment of a gear mechanism 272. FIG. 8 is a side plan view of a leg232 housing the gear mechanism 272 of FIG. 7. FIG. 9 is a sectional viewtaken along line 9-9 in FIG. 8. A high input gear 286 and a low inputgear 282 are selectively engaged by the shift key 274 as previouslydescribed. An idler gear 284 engages the high input gear 286 and the lowinput gear 282. A bevel gear 262 engages the idler gear 284. In thefirst axial position (shown in FIG. 9) the shift key 274 engages thehigh input gear 286 and rotation of an input shaft 252 directly engagesthe high input gear 286 which engages the idler gear 284 which engagesthe bevel gear 262 transferring the rotation of the input shaft 252 to ascrew 254 at a first ratio. In the second axial position (not shown) theshift key engages the low input gear 282 and rotation of the input shaft252 directly engages the low input gear 282 which engages the idler gear284 which engages the bevel gear 262 transferring rotation of the inputshaft 252 to the screw 254 at a second ratio.

Referring now to FIGS. 10-12, FIG. 10 is a perspective view of anotherembodiment of a gear mechanism 372. FIG. 11 is a side plan view of leg332 housing the gear mechanism 372 of FIG. 10. FIG. 12 is a sectionalview taken along line 12-12 in FIG. 11. A high input gear 386 and a lowinput gear 382 are selectively engaged by the shift key 374 aspreviously described. A bevel gear 362 engages the high input gear 386and the low input gear 382. In the first axial position (not shown) theshift key 374 engages the high input gear 386 such that rotation of aninput shaft 352 directly engages the high input gear 386 which engagesthe bevel gear 362 which transfers the rotation of the input shaft 352to a screw 354 at a first ratio. In the second axial position (shown inFIG. 12) the shift key 374 engages the low input gear 382 such thatrotation of the input shaft 352 directly engages the low input gear 382which engages the bevel gear 362 which transfers rotation of the inputshaft 352 to the screw 354 at a second ratio.

The various embodiments of the gear mechanism allow a selection ofhigh/low gear configurations. These allow the legs to be extended at avariety of first and second ratios.

Referring back to FIGS. 1-3, the input shaft 52 has a first end portion100 opposite a second end portion 102. Indicia 104 located on the firstend portion 100 of the input shaft 52 indicates the direction of inputshaft travel necessary to engage the low and high gear portions of thegear mechanism. In the embodiment shown, movement of the input shaft 52in a direction from the first end portion 100 toward the second endportion moves the input shaft towards engagement with the high gearportion of the gear mechanism 72. The indicia could also be any type ofindicia. For example the words “push in =high gear” placed on theoutside of the housing could be used to indicate the direction of thehigh gear position.

Each landing gear assembly includes first and second legs. As describedabove the first and second legs are the same. The only differencebetween the first and second legs in a landing gear assembly is thelocation of the mounting brackets. The first mounting bracket is locatedon the first leg on a side adjacent the second end portion 102 of theinput shaft 52. The second mounting bracket is located on the second legon a side adjacent the first end portion 100 of the input shaft.Mounting options for landing gear include location and position.Location refers to a conventional mount or a reverse mount. A regulartrailer has the support rails located closer to the outside of thetrailer and the landing gear is mounted in a reverse mount as shown inFIG. 13 a. A flat-bed trailer has supporting rails closer to thecenterline and the landing gear is mounted in a conventional mount asshown in FIG. 13 b. The landing gear position refers to roadside orcurbside cranking and corresponds to where an operator will operate theattached crank to extend or retract the landing gear assembly.

It should be understood that the landing gear assembly may be attachedto a trailer such that operation of the landing gear assembly isconsistent with the experience of the operator. For example, mostlanding gear assemblies are set up such that clockwise rotation of thecrank extends the legs and counter-clockwise rotation of the crankretracts the legs. In addition, most landing gear assemblies are set upsuch that the operator engages the high gear by pushing the crankaxially “in” while the low gear is engaged by pulling the crank axially“out”. Some operators prefer to have the crank located on one side ofthe trailer while others prefer it on the other side of the trailer. Forpurposes of discussion, roadside and curbside correspond to the side ofthe trailer adjacent the road and the curb respectively when the traileris on the side of a road but do not require that the trailer be locatedon the side of a road. For a landing gear assembly mounted in a curbsidelocation, an operator would attach a crank to the landing gear assemblyon the curb side of the trailer such that clockwise rotation of thecrank extends the legs and counter-clockwise rotation of the crankretracts the legs and axially movement of the crank toward the trailerengages the high gear and axially movement of the crank away from thetrailer engages the low gear.

As described below, the landing gear assembly can be mounted to anytrailer in any position and any location. The set includes first andsecond legs and at least one connecting member. The connecting membercan include a removable portion to adjust for the shorter distancebetween the first and second legs when mounted on the inside of therails. In the alternative, the set can include two connecting members(one to be used with mounting gear mounted in a conventional mount andone to be used with mounting gear mounted in a reverse mount).

The landing gear assembly can be attached to a new trailer. The landinggear assembly can also be used to replace a worn landing gear assemblyon an existing trailer. To install, the first and second legs aremounted to the trailer with the indicia of both the first and secondlegs facing in the same relative direction. Once mounted the first andsecond legs must be connected. Each leg is then placed in the completelyretracted condition. The connecting member 36 is then installed. Theconnecting member has a pair of holes located in a first end and alongitudinally extending slot located in a second end. The pair of holesis located adjacent the first end at zero and one hundred and eightydegrees and the slot is located adjacent the second end at zero degrees.The connecting member is sized and configured to encompass the inputshafts. The second end of the connecting member is inserted over thesecond input shaft far enough to allow the first end of the connectingmember to be aligned with the first input shaft. The connecting memberis retracted partially from the second shaft and inserted over the firstinput shaft until the pair of holes align with a mounting bore on thefirst input shaft. A bolt is placed through the pair of holes and themounting bore and a nut secures the connecting member to the first inputshaft. The second input shaft is adjusted if necessary to align the slotwith the mounting bore of the second input shaft. A drill insertedthrough the slot and the mounting bore creates a hole in the connectingmember opposite the slot and aligned with the mounting bore. A nut andbolt secure the connecting member to the second input shaft. Theconnecting member translates rotation and axial movement from one of thefirst and second input shafts to the other.

After the landing gear has been mounted to a trailer and the connectingmember has been installed, the landing gear assembly is ready to beoperated. With the connecting member installed, the input shafts and theconnecting member function as a single shaft extending from outside thefirst leg, through the first leg and across and through to the outsideof the second leg. A crank is attached to the single shaft on theappropriate side depending on the mounting position (i.e. curbside orroadside). An operator then turns the crank in a first direction toextend the extension members and a second opposite direction to retractthe extension members.

To operate the landing gear assembly in high gear, the crank is movedaxially towards the leg. This moves the single shaft axially towards theleg such that the shift key in each leg engages the high gear portion ineach leg. Rotation of the crank causes the single shaft to engage thehigh gear portion of the gear mechanism in each leg such that theextension member in each leg is extended or retracted.

To operate the landing gear assembly in low gear, the crank is movedaxially away from the leg. This moves the single shaft axially such thatthe shift key in each leg engages the low gear portion in each leg.Rotation of the crank causes the single shaft to engage the low gearportion of the gear mechanism in each leg such that the extension memberin each leg is extended or retracted.

In high gear, each leg extends or retracts a greater distance perrevolution of the shaft than in low gear. The effect being that if theconnecting member rotates at a set rate about its axis, the legs willextend or retract a greater distance per revolution when the legs are inhigh gear than when the legs are in low gear.5

When necessary, the crank can be attached on the other side (from theside described above) of the mounted landing gear assembly. In thisconfiguration, rotation of the single shaft in the first direction willretract the lower members of each leg and rotation of the single shaftin the opposite direction will extend the lower members of each leg.Axial movement of the single shaft away from the leg engages the shiftkey in each leg with the high gear portion of the gear mechanism in eachleg. Axial movement of the single shaft away from the leg engages theshift key in each leg with the low gear portion of the gear mechanism ineach leg.

The landing gear assembly may be used with a variety of types oftrailers. For example, the landing gear assembly may be used with asemi-trailer. The semi-trailer could be a flat bed trailer or a box typetrailer. A single leg could be used with a goose neck trailer or asmaller utility trailer. A manufacturer making many different types oftrailer could equip all these trailers using the landing gear assemblyof the present invention reducing the inventory needs of themanufacturer. In addition, the singular configuration of the first andsecond legs simplifies the production of the landing gear assembly.

In the embodiment shown, the housing and the extension member aresubstantially rectangular in shape and the connecting member iscylindrical in shape. However, it is to be understood that other shapesand configurations may be employed without departing from thisinvention.

As various changes could be made in the above constructions and methodswithout departing from the scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense. Thus, the breadth and scope of the present inventionshould not be limited by any of the above-described exemplaryembodiments, but should be defined only in accordance with the followingclaims appended hereto and their equivalents.

1. A landing gear assembly for supporting a trailer, the landing gearassembly comprising: a first leg and a second leg, each leg having ahousing, an input shaft, a gear mechanism, and an extension potion, thehousing being adapted to connect the leg to a trailer, the input shafthaving a first end a portion and a second end portion, the input shaftextending through the housing and being axially movable between a firstposition and a second position and being rotationally movable, the gearmechanism being housed in the housing and having a high gear and a lowgear, the gear mechanism being operatively connected to the input shaftsuch that the input shaft engages the low gear when in the secondposition and the input shaft engages the high gear when in the firstposition, the extension portion being telescopically movable withrespect to the housing and being operatively connected to the gearmechanism such that rotation of the input shaft moves the extensionportion with respect to the housing, the extension portion being movablea first distance when the input shaft is rotated one revolution while inthe first position, the extension portion being movable a seconddistance when the input shaft is rotated one revolution while in thesecond position, the first distance being greater than the seconddistance; and a cross shaft adapted to operatively connect a first endportion of one of the input shafts with a second end portion of theother of the input shafts such that axial movement of one of the inputshaft of the first and second legs causes axial movement of the other ofthe input shafts of the first and second legs and rotation of one of theinput shaft of the first and second legs causes rotation of the other ofthe input shafts of the first and second legs; wherein the first andsecond legs are adapted to be attached to a trailer and connected to oneanother with the cross shaft such that when the input shaft of one ofthe first and second legs is moved to the first position the input shaftof the other of the first and second legs is moved to the first positionand when the input shaft of one of the first and second legs is moved tothe second position the input shaft of the other of the first and secondlegs is moved to the second position and when the input shaft of one ofthe first and second legs is rotated one revolution the input shaft ofthe other of the first and second legs is rotated one revolution.
 2. Alanding gear assembly as set forth in claim 1 wherein We gear mechanismof the first and second legs further comprises a threaded screw having ascrew axis, the threaded screw being longitudinally fixed in the housingand free to rotate about the screw axis; a bevel gear operativelyconnected to the threaded screw; and a riser nut fixed longitudinally inthe extension portion and defining a threaded opening, the threadedopening being adapted and configured to engage the screw such thatrotation of the screw causes the riser nut to move in a direction of thescrew axis with respect to the screw, wherein the bevel gear isoperatively driven by the low gear when the input shaft is in the firstposition and is operatively driven by the high gear when the input shaftis in the second position such that rotation of the input shaft causesrotation of the bevel gear and the threaded screw.
 3. A landing gearassembly as set forth in claim 2 wherein the gear mechanism of the firstand second legs further comprises an idler shaft positioned in thehousing parallel to the input shaft, an idler gear on the idler shaft,the high input gear on the input shaft being in engagement with theidler gear and the bevel gear, and the low input gear on the input shaftbeing in engagement with the idler gear.
 4. A landing gear assembly asset forth in claim 2 wherein the gear mechanism of the first and secondlegs further comprises an idler shaft positioned in the housing parallelto the input shaft, a high input gear on the idler shaft in engagementwith the bevel gear, the low input gear on the input shaft in engagementwith the high input gear on the idler shaft, and the high input gear onthe input shaft in engagement with the high input gear on the idlershaft.
 5. A landing gear assembly as set forth in claim 2 wherein thegear mechanism of the first and second legs further comprises the lowinput gear on the input shaft being in engagement with the bevel gearand the high input gear on the input shaft being in engagement with thebevel gear.
 6. A landing gear assembly as set forth in claim 1 whereinthe first and second legs further comprise a shift keys the shift keyextending away from the input shaft and being adapted to operativelyconnect the input shaft to the gear mechanism and being configured toengage the low gear when the input shaft is in the second position andto engage the high gear when the input shaft is in the first position.7. A landing gear assembly as set forth in claim 6 wherein the shift keyincludes a gear cog portion and a gear engaging portion, the gear cogportion being adapted and configured to engage the low gear when theinput is in the second position and the gear engaging portion beingadapted and configured to engage the high gear when the input shaft isin the first position.
 8. A landing gear assembly as set forth in claim1 wherein each of the first and second legs comprises a mountingbracket, on one of the first and second legs the mourning bracket beinglocated on the housing adjacent the fist end portion of the input shaftand on the other of the first and second legs the mounting bracket beinglocated on the housing adjacent the second end portion of the inputshaft.
 9. A semi trailer comprising the landing gear assembly ofclaim
 1. 10. A method of modifying a semi trailer comprising: providinga landing gear assembly as set forth in claim 1; attaching the landinggear assembly to the semi trailer.
 11. A landing gear assemblycomprising: a trailer, first and second legs attached to the trailer,each leg being configured to selectively extend and retract in length;and a connecting member operatively connecting the first and secondlegs, the connecting member being rotatable about an axis relative tothe trailer and being axially movable a first position and a secondposition; wherein the first and second legs are each configured toextend in length a first amount per revolution of the connecting memberabout the axis of the connecting member when the connecting member is inthe first position and the first and second legs are each configured toextend in length a second amount per revolution of the connecting memberabout the axis of the connecting member when the connecting member is inthe second position, the first amount being greater than the secondamount.
 12. A landing gear assembly as set forth in claim 11 wherein theconnecting member is at least partially cylindrical.
 13. A landing gearassembly as set forth in claim 11 wherein each of the first and secondlegs further comprises a gear mechanism, the gear mechanism having afirst gear portion and a second gear portion, the first gear portionbeing operatively connected to the connecting member when the connectingmember is in the first position and the second gear portion beingoperatively connected to the connecting member when the connectingmember is in the second position.
 14. A landing gear assembly as setforth in claim 11 wherein the connecting member includes a first inputshaft extending through the first leg and a second input shaft extendingthrough the second leg.
 15. A method comprising: providing a trailer,the trailer including a landing gear assembly, the landing gear assemblyhaving first and second legs attached to the trailer and a connectingmember operatively connecting the first and second legs, each leg beingconfigured to selectively extend and retract in length, the connectingmember being rotatable about an ads relative to the trailer; causing theconnecting member to rotate about the axis of the connecting member at afirst rate such that the first and second legs extend in length a firstamount per revolution of the connecting member; causing the connectingmember to rotate about the axis of the connecting member at the firstrat such that the first and second legs extend in length a second amountper revolution of the connecting member, wherein the first amount isgreater than the second amount.
 16. A method as set forth in claim 15wherein the providing step further comprises providing each leg with agear mechanism having a high gear portion and a low gear portion, theconnecting member being rotatable about an axis relative to the trailerand being axially movable between a first position and a second positionsuch that the connecting member engages the high gear portion in thefirst position and the connecting member engages the low gear portion inthe second position, the method further comprising the step of movingthe connecting member from the first position to the second positionafter causing the connecting member to rotate at the first rate andbefore causing the connecting member to rotate at the second rate.
 17. Alanding gear assembly comprising: a first leg being adapted to attach toa trailer, the first leg including a first housing, a first input shaft,a first gear mechanism, and a first extension portion, the first inputshaft having a first end portion opposite a second end portion, thefirst input shaft extending through the first housing and beingrotatable about a first axis relative to the first housing and beingaxially movable between a first position and a send position, the firstgear mechanism having a first high gear and a first low gear and beingoperatively connected to the first input shaft such that the first inputshaft engages the first low gear when in the second position and thefirst input shaft engages the first high gear when in the firstposition, the first extension portion being telescopically movable withrespect to the first housing and being operatively connected to thefirst gear mechanism such that rotation of the first input shaft movesthe first extension portion with respect to the first housing, the firstextension portion being movable a first amount when the first inputshaft is rotated one revolution while in the first position, the firstextension portion being movable a second amount when the first inputshaft is rotated one revolution while in the second position, the firstamount being greater than the second amount.
 18. A landing gear assemblyas set forth in claim 17 further comprising: a second leg including asecond housing, a second input shaft, a second gear mechanism, and asecond extension portion, the second input shaft having a third endportion opposite a fourth end portion, the second input shaft extendingthrough the second housing and being rotatable about a second axisrelative to the second housing and being axially movable between a thirdposition and a fourth position, the second gear mechanism having asecond high gear and a second low gear and being operatively connectedto the second input shaft such that the second input shaft engages thesecond low gear when in the fourth position and the second input shaftengages the second high gear when in the third position, the secondextension portion being telescopically movable with respect to thesecond housing and being operatively connected to the second gearmechanism such that rotation of the second input shaft moves the secondextension portion with respect to the second housing, the secondextension portion being movable a third amount when the second inputshaft is rotated one revolution while in the third position, the secondextension portion being movable a fourth amount when the second inputshaft is rotated one revolution while in the fourth position, the thirdamount being greater than the fourth amount, the third amount beingequal to the first amount and the fourth amount being equal to thesecond amount, and a connecting member adapted to operatively connectthe first leg to the second leg.
 19. A landing gear assembly as setforth in claim 18 further comprising: a trailer attached to the firstand second legs; and wherein the connecting member is operativelyconnected to the first and second legs such that axial movement of thefirst input shaft transfers axial movement to the second input shaft androtation of the first input shaft transfers rotation to the second inputshaft such that when the first input shaft is moved to the firstposition the second shaft is moved to the third position and when thefirst input shaft is moved to the second position the second input shaftis moved to the fourth position and when the first input shaft isrotated one revolution the second input shaft is rotated one revolution.20. A landing gear assembly as set forth in claim 17 further comprising:a trailer attached to the first leg. 21-38. (canceled)